Steam-condensing and feed-water system



Sept. 7,1926. 1,599,334

c. R. LANG. I STEAM GONDENSING AND FEED 6mm: SYSTEM Filed Sept. 10, 1925To BOILER FEED Pum FIG m/rm Ta/P. C/LarZe-s 27% mar:

Patented Sept. 7, 1926 UNITED STATES CHARLES RUSSELL Lane, or GLASGOsco'rLAnn, ASsreNoR T0 e. a J. WEIR,

LIMITED, or GLASGOW; SCOTLAND.

rEAMpoNnEnsING Ann FEED-"WATER YSTEM.

Application filed September 10, 1923, Serial No. 661,945, and in GreatBritain October 12, 1922.

This invention relates tosteam condensing and feed water systems of thetype, at present in operation, which are characterized as follows 1 Thewater of condensation is withdrawn from the main condenser by awater-extrad takes place through an. automatic overflow grammatlc,

or relief valve. I

Provision is also made, for discharging water when necessary from thesaid feed tank through a return conduit to the main condenser, or to theSuction of the water extraction pump. This discharge of water takesplace through an automatic return flow valve on the said return conduit.This return-flow valve is'sometimes controlled by a float situated in awell in thebottom of the condenser or in a tank in communication withthe condenser.

In such systems there is, under certain conditions, a flow of water outof the main feed conduit through the said overflow or relief valve intothe feed tank and at the same time a return or counter-flow of waterfrom the ,feed tank through the said returnflow valve into the main feedconduit by way of the water-extraction pump. This simultaneous flow andcounter-flow is a max imum when the plant is operating at low powers: itis a minimum when the plant is operating at full power: it absorbsenergy without giving any useful efiect except that it promotesstability'of operation of the plant. I

A further disadvantage of thisfiow and counter-flow is that the feedwater, which which has been freed of nearly all its air inthe condenser,is allowed to absorb air in the feed tank which is open to theatmosphere. This is an objection as itiis always desirable to keep thefeed water as ,free of air as possible.

The object of thepresent invention is to eliminate this simultaneousflow and coun-V ter-flow and reduce the efilux and influx of feed waterfrom and to the feed tank.

- The present invention-which will be de': fined in the annexed;claimsfinvolves the r operation o'fthe overflow or relief valve, as

water level.

well as the return-flow valve', by a float (an independent float.for'each valve) situated in a well in'the bottom'of the condenser or ina tank which is connected to the condenser and in' whichthe waterle'velis maintained the Same as in the condenser and in the placing of thesaid two floats at different levels for a purpose which will behereinafter explained. I

The accompanying drawings illustrate the carrying of the presentinvention into effect in one convenient manner.- v -F1g. 1 1s a generalarrangement-dia- Fig. 2 is a vertical section of the 'overflow or reliefvalve. 1 i

Fig. 3 is a vertical section of the vice for controlling this'valve.

w is the main condenser, c the mainteed conduit, wthe water-extractionpump. 01 is the automatic valveon the return conduit 4! z is a'tank inconnection with the bottomof the condenser,-'which tank contains a floatwhich, through a relay, operates the valve (1. This relay device and itsemployment for this purpose are not new. The

device need not be described in detail. It w1ll suflice to say thatthearrangement is such that the valve d closes with rise of water levelin the tank, and opens'with fall of The water level inthe tank is thesame as that in thebottom of the condenser due to the pipeconnections t,s, 1 p.

a istheoverfiow or relief valve. connected-to a piston Z) which works ina cylinder '0. 7 is a compression spring which tends to close the valve.The'cylinder 0- is hydraulically connected to the main feed conduit onthe discharge Side of the water extraction pumpby means of a small pipeSituated on this pipe 6 is a relay valve 9 e. Which is controlled'byafloat h' pla'ced-in a tank Q. 'The float operates the valve 9 through alever 'VVhen the float falls, it opens the valve g and allows escape'ofwater from the pipe e, thus causing a fall of It is pressure in'thispipe; The chamberm of the valved is normally kept under pressure bymeans of the pipe 6. lVhen the pressure in this pipe falls, the pressureconsequently falls in the chamber m. The pressure on the piston bis'thusrelieved, and the spring f acts to close the valve'a. The consequence isthat fall inthe water level in thetank Q causes the valve a to close,and rise in the waterl-evel causes the valve. to open. When the valve isopen, water passes from the feed conduit through the pipe 0 to a feedtank. The water level in the tank 9 is maintained the same as that inthe condenser by means of the pipe connections .32, r, n.

The float it is set at a higher level than the float in the tank a whichcontrols the valve ZZ. Six inches is a good working diliterence inwaterlevel in the generality of cases. The two water levels areindicated by the chain lines 2, and 3. The normal working water level inthe condenser is at the lower float level: in this position the overflowvalve is shut so that no flow out of the main feed conduit can takeplace. v Having thus described my invention, what I claim as new anddesire to secure by Letters Patent is r 1-; In a steam condensing andfeed water system, in combination, a condenser, a boilerfeed pump, amain teed conduit which extends from the said condenser to the saidboiler teed pump, a water-extraction pump which withdraws the water fromthe said condenser and delivers it into and along the said main feedconduit, a feed tank, an automatic overflow valve whereby feed water maybe discharged from the said main teed conduit into the said teed tank, atank connected. to the said condenser so that the waterlevel in the tankand in the condenser are the same, a float in the said tank, ii'ieanswhereby the said float operates to open the saidoverflow valve with arise of water, level and' to close the said valve with fall in waterlevel, a return conduit extending from the said feed tank to the suctionofthe said water extraction pump, an automatic return-flow valve on thesaid return conduit, a second -tank connected to the said condenserso,-that the water level in the tank and in the "condenser are the same,float in this tank located at a'lower level than the first-mentionedfloat, and means whereby the second-mentioned float operates to closethe said return-flow valve with rise of, water level and to open thesaid return-flow valve with fall of water level.

2. In a steanrcondensing and feed water system, in combination,a'condenser, a boiler teed pump, a main teed conduit. which extends fromthe said condenserto the said boiler feed pump, a water-extraction pumpwhich withdraws the water from the said condenser and delivers it intoand along the said main teed conduit, a feed tank, an automatic overflowvalve whereby feed water may be discharged from the said main feedconduit into the said teed tank,

a heat controlled by rise and an of water level in the said condenser,means whereby the said fioatoperates to open the saidoverflow valve withrise of Water leveland to close the said valve with {all water level, areturn conduit extending from the said feed tank to the suction of thesaid watereXtracti-on pump, an autoinaticreturn-flow valve on the saidreturn conduit, a second float controlled by rise and fall of waterlevel in the said condenser and located at a lower level than thefirst-mentionedfioat, and means whereby the second-mentioned floatoperates to close the said return-flow valve with rise o'f water leveland to open,

may be discharged from thesaid in'ain teed conduit into the said (feedtank, a tank connected to the said Condenser so that the water level inthe tank and in the condenser are the same,.a floati n the said tank, arelay valve opera'tively connected to the said float, and means wherebythe said relay valve functions to open the saidoverflow valve with riseof water level and to close the :said valve with fall in water level, areturn conduit extending from the said iteed tank to the suction of thesaid water-extraction; pump, an automatic, -re turn-flow valve on thesaid return conduit, a second tank connected to the said condenser sothat thewate'r level in the tank and in the condenser are the same, afloat in this tank located at a lower level than the first-mentionedfloat, and means where- :the second-mentioned float operates to closethe said return-flow valve. with rise or water level and to open thesaid return-flow valve with fall of water level.

4. In a steam condensing and feed water system, in combinatiom acondenser, a boiler feed punp, afmain ,feed'eonduit which extends fromthe said condenser to the said boiler feed vpump, awater-extraction pumpwhich withclrawsth'e water from the said condenser and delivers'it intoand alon'g the said main feed conduit, a "feed tank, an automaticoverflow valve whereby feed water may be discharged from "the said inainfeed conduit intovthe said ifeed'tank, 'a float c ntrolled by rise andlall'ol water level in the said condenser, a relay valve 'operativelyconnected to the said float, and means whereby the said relay valvefunctions to open the. said overflow valve with rise of water level andto close the said valvewith fall'in water leveha return conduitextend;ing from thesaid feed tank to the'su'ction or the said water-extractionpump, an autosaid return-flow valve with rise of Water matic return-flowvalve on the said return conduit, a second float controlled by rise andfall of water level in the said condenser and located at a lower levelthan the first- Inentioned float, and means -whereby thesecond-mentioned float operates to close the level and to open the saidreturn-flow valve with fall of water level. V e

5. In a steam condensing and feed water system, in combination, acondenser, a boiler feed pump, a main feed conduit which extends fromthe said condenser to the said boiler feed pump, a water-extraction pumpwhich withdraws the water from the said condenser and delivers it intoand along the said main feed conduit, a feed tank, an automatic overflowvalve whereby feed water may be discharged from the said main feedconduit into the said feed tank, atank connected to the said condenserso that the water level in the tank and in the condenser are the same, afloatin the said tank, a piston connected to said overflow valve, a 7cylinder In which the said piston works, a;

float operates to close the said return-flow valve with rise of waterlevel and to open the said return-flow valve with fall of water level.

' 6. In a steam condensing and feed Water system, in combination, acondenser, a boiler :teed pump, a main feed conduitwhich extends fromthe said condenser to the said i boiler feed pump, a water-extractionpump which Withdraws the water from the said condenser and delivers itinto and along the said main feed conduit, a feed tank, an automaticoverflow valve whereby feed water may be discharged from the said mainfeed conduit into the saidieed tank, a float con trolledby rise and fallof water level in the said condenser, a piston connected to said 7overflow valve, a cylinder in which the'said piston works,a pipesupplying said cylinder withwater under pressure, a relay valveoperatively connected to the said float and controlling the escape ofwater from'the said pipe, a return conduit extending from the said feedtank to the suction of the said water-extraction pump, an automaticreturnflow valve on the said return conduit, a second float controlledby rise and fall of water level in the said condenser and located at alower level than the first-mentioned.

float, and means whereby the secondmentioned float operates to close thesaid returnflow valve with rise of water level and to open the saidreturn-flow valve with fall or water level. I v

I hereby sign my name to this specification.

CHARLES BUS-SELL LANG.

